There may also a lot more to be discovered about the brain and body too, in the area of some connection between the fascia and the immune system (cf. the anecdotal connection between things like yoga and "internal" martial arts and health)

We have more than anecdotal evidence. While there still things to be discovered about the interaction between fascia and the immune system, it's already quite clear that if fascia get's too loose and cells rub against each other too much they die and you get inflammation.

Macrophage also have it harder to get around when tissue is very tight.